Reaction time and attention in schizophrenia: a comment on K. H. Nuechterlein's critical evaluation of the data and theories.

Abstract

In his exhaustive review, Nuechterlein (1977) has discussed both the earliest and the most recent contributions to the literature on reaction time (RT) in schizophrenia. Instead of synopsizing this summary or introducing additional research, we have decided to focus on a circumscribed aspect of the literature. In this paper we will be concerned only with the Shakow set paradigm and the Sutton and Zubin cross-modality technique, as well as with their respective theoretical interpretations. Specifically, our objectives are: (1) to compare and contrast both RT techniques in terms of the procedures employed and the variables manipulated; (2) to point out an aspect of the Shakow set paradigm that seems to have been generally overlooked; and (3) to discuss and respond to some comments on the Zubin neuronal trace model. As a necessary preliminary, we will review the two RT procedures in terms of their task requirements and relevant variables. Superficial comparisons of the set and cross-modal RT paradigms often obscure essential differences in method. These discrepancies, in turn, relate to fundamental distinctions between the theoretical constructs and subsystems of attention that are under study in each procedure. In the set procedure, each trial is usually initiated by a warning signal. Thus, in most experiments, the subject has no control over the timing of the onset of a trial. The warning signal initiates a preparatory interval (PI) or waiting period. The subject may have no information about the duration of the PI (uncertain condition), or he may be told whether it will be long or short (certain condition). The duration of the PI may range from a very